Counterbalancing means for multiple drills



COUNTERBALANCING MEANS FOR MULTIPLE DRILLS Original Filed Dec. 2. 1922 s Sheets-Sheet 1 K1 lNVENTOR 9. wag/W ATTORNEY May 15, 1928. 1,669,915

I J. M. RUSNAK COUNTERBALANCING MEANS FOR MULTIPLE DRILLS Original Filed Dec. 2, 1922 a Sheets-Sheet 2 ATTO R N EY May 15, 1928. 1,669,915

J. M. RUSNAK COUNTERBALANCING MEANS FOR MULTIPLE DRILLS Original Filed Dec. 2. 1922 :5 Sheets-Sheet 3 ATTORNEY g adds an improved counterbalancing mechw Patented May 15,1928.

UNITED STATES :Parsnr names.

comma. BUSNAK, or nmroRncon vne'rIcur, assrcnor. me name wnrrnny Ior nnw yomc, n. Y., acoaronarron or New JERSEY.

' 'COU'NTERBALA-NCING MEANS [FOR MULTIPLE DRIL'LS.

Original application filed December 2, 1922, Serial No. 604,482. Divided and this application flled February 4, 1926.

This invention relatesprimarily to drill- .ing machines and armreespecially to-a multiple spindle drilling machine. Such a machine ordinarily comprises a supporting column on which .a drill spindle supporting head is slidably mounted. Means is pro- .vided for rotating the .drill spindle o r spindles in sthe head and other means is provided for moving the zheadslow'ly downward nthe-column ifor feeding or movingit rapidlyin'either direction for traversing.

.One'ohject of the invention is to provide an improved drilling machine of the type statediadapted to functiongeither as a semiautomatic machine wherein all the feeding and traversing movements of the head are power operated and controlled automatically or [as a plain drilling machine wherein only the feeding movement is performed by power, the head being .adapted to be reach lly traversed in both directions by hand.

Anotherohject otthe invention is to pronism for the .drill ,spindle supporting head, such mechanism providing for an accurate counterbalancing .of the head and safety holding .means :in connection therewith for preventing the dropping of the head should the counterbalancingmechanism fail.

Withflthexaboveand other-objects in view, myjnventionconsists in the features of con- Struction-a-nd operation set forth in the following specification and illustrated in the accompanying drawings. In such drawings annexed hereto and forming a partof this specification, :I have shown my invention as embodied in a multiple spindle drilling machine but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

Referring to the figures of the drawings:

Figure 1 is a front elevation of a complete multiple spindle drilling machine comprising my invention. 7

Fig. 2 is a side elevation thereof.

Fig. 3 is a perspective view showing my improved drill head counter-balancing mechanism. v

In the above mentioned drawings, I have shown but ne embodiment of the invention which is now decmed preferable,but it is to be understood that changes and modifications may be .made wltllllltlle scope of the appended claims without departing from the spirit of the invention.

ing machine and in its .more complex form becomes a semi-automatic drillingmachine.

In shop terms and insthe usual mechanical parlance, such a SGlDlrZl-lliOll'lfiilC drilling machine as herein shown and described is known as an automatic multiple spindle drilling machine. However, since such machine. .13 not 1n fact fully automatic, the same ,is herem termed semi-automatic.

The original cost of a plain drilling machine isconsiderably less than anautomatic or semi-automatic machine and such plain machine is more adapted to certain classes of work. By adding certain other mechanism to the plain drilling machine illustrated herein, 'the same may be converted into a semiautomatic drilling machine, which machine is also adapted to-be used as a plain drilling machine when desired. By such -a standardized construction, the manufacture of these two .types of drilling machines is greatly simplified and the adapta-' bilityoithe sen'iiaantomatic machine to use as a hand machine is of considerable ad vantage.

Either of theefarms of'the invention requiresthe use of a counterbalancing means for the vertically movable head supporting the drill spindles so that this head may be raised or lowered manually without undue exertion, or may be raised or lowered by power without a large expenditure of power.

This application forms a division of my Patent No. 1,594,429 granted August 3, 1926, in which the complete machine is disclosed in detail. 1

Referring more specifically to the drawings by reference characters, 1 indicates the base and 2 the column of my improved drilling machine. Mounted for vertical sliding movement on the column is a drill head 3. The head 3 is preferably slidably mounted on the column upon ways 5 on the column. A pair of straps 7 secured to the head by bolts 8 engage rear surfaces of the ways 5 and hold the projections firmly seated against the column. In this manner the head is firmly supported and accurately guided in its movements on the column.

Ina large machine of the type illustrated, the weight of the head 3 is considerable. It is therefore necessary to counterbalance this weight and this function is preferably accomplished by the novel counterbalancing arrangement. shown in Figs. 2 and 3. A main weight 9 movable vertically in the center of the column is connected to thehead 3 by a pairof cableslO passing over sheaves lland 12. The cables, at one end, are respectively secured to the ends of an equal izer bar 13 pivoted at its center to the weight 9 whereby each cable supports an equal portion of't'he weighty One cable is secured rigidly to the head at 14. The other cable is connected to an element 15 slidably mounted in the head. A spring 16 between the lower end of the element 15 and a bushing 17 secured to the head normally forces the element downwardly. The tension on the cable holds the spring compressed. A washer 18 on the element limits the upward movement of the element by contacting with the head. 3. A linkll) operatively connects the element 15 with an arm 20 on'a shaft 21 in the head and provided thereon is a toothed member 22 adjacent a vertically extending rack 23 on the column. Should the cable break or the tension thereon be released for any cause, the expansion of the spring 16 will move the member 22 about its pivot and engage the teeth (hereon with the rack 23 thereby sup 'iorting the head against downward movement.

The rear wall of the column is curved transversely to receive therein a second weight 24 movable vertically within a guard 26 secured to thecolumn 2. A centrally located cable passing over sheaves 27 connects the head 3 to the weight 24. The

weight 24: is provided with a plurality of varied sized removable sections 24: whereby to compensate for the weight of any parts added or removed from the head. An opening 26', normally closed by a removable cover plate, isformed in the guard 26 Whereby the operator may have ready access to the weights 24'. In this manner the head 3 may be accurately counterbalanced for each particular drill spindle arrangement used by the machine for different 'clrilling operations. Also tlievsaf'ety device in connection with one of the cables 10 positively prevents a dropping of the drill head 3 shouldthe counterbalaneing mechanism for any reason fail to support the same.

\Vhat I claim is:

1. in a machine of the class described, the combination of a column, a head slidable vertically on the column, a pair of counterweights, one counterweight being movable vertically in the column and the other being exposed, an equalizing plate pivoted to the counterweight in the column, a pair of cables having their ends respectively connected to a. fixed part of the head and to the ends of the equalizing plate, the exposed counterweight being formed in removable sections whereby the head may be accurately counter balanced, and a third cable between the said pair of cables operatively connecting the exposed counterweight with the head.

2. In a drilling machine, the combination of a base, a column thereon, a drill head slidable on the column, a plurality of spindles mounted in the head, a driving shaft supported on the base, an operative connection including a vertically extending belt from the shaft to the spindles. a pair of countcrweights, one counterweight being movable vertically in the column and the other being positioned adjacent thereto, and movable vertically between the opposed portions O'lf l'lle said belt, and cables opcratively connecting the counterweights to a lixed part of the head for counterbalaneing the same, the said other counterweight being formed in removable sections \vherebythe headmay be accurately counterbalanced In testimony whereof, I hereto.aflix my signature.

JOHN M. RUSNAK. 

